Yes, I know that I should use listener or visitor generated by antlr tool.
I want to use visitor pattern, but I don't know how to use it exactly.
I asked for pointing a way (or maybe some tutorial) how to use visitor pattern in Python.
To learn the tool I've very simple grammar now:
grammar Gram;
prog: (expr NEWLINE)* ;
expr: left=expr op=('*'|'/') right=expr
| left=expr ('+'|'-') right=expr
| atom=INT
| '(' expr ')'
;
NEWLINE : [\r\n]+ ;
INT : [0-9]+ ;
And the visitor generated looks like:
class GramVisitor(ParseTreeVisitor):
def visitProg(self, ctx):
return self.visitChildren(ctx)
def visitExpr(self, ctx):
return self.visitChildren(ctx)
Could you explain me what should I do further on this simple example?